/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef PINYINIME_INCLUDE_SPELLINGTRIE_H__
#define PINYINIME_INCLUDE_SPELLINGTRIE_H__

#include <stdio.h>
#include <stdlib.h>
#include "./dictdef.h"
#include <QFile>

namespace ime_pinyin
{

	static const unsigned short kFullSplIdStart = kHalfSpellingIdNum + 1;

	// Node used for the trie of spellings
	struct SpellingNode {
		SpellingNode *first_son;
		// The spelling id for each node. If you need more bits to store
		// spelling id, please adjust this structure.
		uint32 spelling_idx: 27;
		uint32 num_of_son: 5;
		char char_this_node;
		unsigned char score;
	};

	class SpellingTrie
	{
	private:
		static const int kMaxYmNum = 64;
		static const size_t kValidSplCharNum = 26;

		static const uint16 kHalfIdShengmuMask = 0x01;
		static const uint16 kHalfIdYunmuMask = 0x02;
		static const uint16 kHalfIdSzmMask = 0x04;

		// Map from half spelling id to single char.
		// For half ids of Zh/Ch/Sh, map to z/c/s (low case) respectively.
		// For example, 1 to 'A', 2 to 'B', 3 to 'C', 4 to 'c', 5 to 'D', ...,
		// 28 to 'Z', 29 to 'z'.
		// [0] is not used to achieve better efficiency.
		static const char kHalfId2Sc_[kFullSplIdStart + 1];

		static unsigned char char_flags_[];
		static SpellingTrie *instance_;

		// The spelling table
		char *spelling_buf_;

		// The size of longest spelling string, includes '\0' and an extra char to
		// store score. For example, "zhuang" is the longgest item in Pinyin list,
		// so spelling_size_ is 8.
		// Structure: The string ended with '\0' + score char.
		// An item with a lower score has a higher probability.
		size_t spelling_size_;

		// Number of full spelling ids.
		size_t spelling_num_;

		float score_amplifier_;
		unsigned char average_score_;

		// The Yunmu id list for the spelling ids (for half ids of Shengmu,
		// the Yunmu id is 0).
		// The length of the list is spelling_num_ + kFullSplIdStart,
		// so that spl_ym_ids_[splid] is the Yunmu id of the splid.
		uint8 *spl_ym_ids_;

		// The Yunmu table.
		// Each Yunmu will be assigned with Yunmu id from 1.
		char *ym_buf_;
		size_t ym_size_;  // The size of longest Yunmu string, '\0'included.
		size_t ym_num_;

		// The spelling string just queried
		char *splstr_queried_;

		// The spelling string just queried
		char16 *splstr16_queried_;

		// The root node of the spelling tree
		SpellingNode *root_;

		// If a none qwerty key such as a fnction key like ENTER is given, this node
		// will be used to indicate that this is not a QWERTY node.
		SpellingNode *dumb_node_;

		// If a splitter key is pressed, this node will be used to indicate that this
		// is a splitter key.
		SpellingNode *splitter_node_;

		// Used to get the first level sons.
		SpellingNode *level1_sons_[kValidSplCharNum];

		// The full spl_id range for specific half id.
		// h2f means half to full.
		// A half id can be a ShouZiMu id (id to represent the first char of a full
		// spelling, including Shengmu and Yunmu), or id of zh/ch/sh.
		// [1..kFullSplIdStart-1] is the arrange of half id.
		uint16 h2f_start_[kFullSplIdStart];
		uint16 h2f_num_[kFullSplIdStart];

		// Map from full id to half id.
		uint16 *f2h_;

#ifdef ___BUILD_MODEL___
		// How many node used to build the trie.
		size_t node_num_;
#endif

		SpellingTrie();

		void free_son_trie(SpellingNode *node);

		// Construct a subtree using a subset of the spelling array (from
		// item_star to item_end).
		// Member spelliing_buf_ and spelling_size_ should be valid.
		// parent is used to update its num_of_son and score.
		SpellingNode *construct_spellings_subset(size_t item_start, size_t item_end,
		        size_t level, SpellingNode *parent);
		bool build_f2h();

		// The caller should guarantee ch >= 'A' && ch <= 'Z'
		bool is_shengmu_char(char ch) const;

		// The caller should guarantee ch >= 'A' && ch <= 'Z'
		bool is_yunmu_char(char ch) const;

#ifdef ___BUILD_MODEL___
		// Given a spelling string, return its Yunmu string.
		// The caller guaratees spl_str is valid.
		const char *get_ym_str(const char *spl_str);

		// Build the Yunmu list, and the mapping relation between the full ids and the
		// Yunmu ids. This functin is called after the spelling trie is built.
		bool build_ym_info();
#endif

		friend class SpellingParser;
		friend class SmartSplParser;
		friend class SmartSplParser2;

	public:
		~SpellingTrie();

		inline static bool is_valid_spl_char(char ch)
		{
			return (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z');
		}

		// The caller guarantees that the two chars are valid spelling chars.
		inline static bool is_same_spl_char(char ch1, char ch2)
		{
			return ch1 == ch2 || ch1 - ch2 == 'a' - 'A' || ch2 - ch1 == 'a' - 'A';
		}

		// Construct the tree from the input pinyin array
		// The given string list should have been sorted.
		// score_amplifier is used to convert a possibility value into score.
		// average_score is the average_score of all spellings. The dumb node is
		// assigned with this score.
		bool construct(const char *spelling_arr, size_t item_size, size_t item_num,
		               float score_amplifier, unsigned char average_score);

		// Test if the given id is a valid spelling id.
		// If function returns true, the given splid may be updated like this:
		// When 'A' is not enabled in ShouZiMu mode, the parsing result for 'A' is
		// first given as a half id 1, but because 'A' is a one-char Yunmu and
		// it is a valid id, it needs to updated to its corresponding full id.
		bool if_valid_id_update(uint16 *splid) const;

		// Test if the given id is a half id.
		bool is_half_id(uint16 splid) const;

		bool is_full_id(uint16 splid) const;

		// Test if the given id is a one-char Yunmu id (obviously, it is also a half
		// id), such as 'A', 'E' and 'O'.
		bool is_half_id_yunmu(uint16 splid) const;

		// Test if this char is a ShouZiMu char. This ShouZiMu char may be not enabled.
		// For Pinyin, only i/u/v is not a ShouZiMu char.
		// The caller should guarantee that ch >= 'A' && ch <= 'Z'
		bool is_szm_char(char ch) const;

		// Test If this char is enabled in ShouZiMu mode.
		// The caller should guarantee that ch >= 'A' && ch <= 'Z'
		bool szm_is_enabled(char ch) const;

		// Enable/disable Shengmus in ShouZiMu mode(using the first char of a spelling
		// to input).
		void szm_enable_shm(bool enable);

		// Enable/disable Yunmus in ShouZiMu mode.
		void szm_enable_ym(bool enable);

		// Test if this char is enabled in ShouZiMu mode.
		// The caller should guarantee ch >= 'A' && ch <= 'Z'
		bool is_szm_enabled(char ch) const;

		// Return the number of full ids for the given half id.
		uint16 half2full_num(uint16 half_id) const;

		// Return the number of full ids for the given half id, and fill spl_id_start
		// to return the first full id.
		uint16 half_to_full(uint16 half_id, uint16 *spl_id_start) const;

		// Return the corresponding half id for the given full id.
		// Not frequently used, low efficient.
		// Return 0 if fails.
		uint16 full_to_half(uint16 full_id) const;

		// To test whether a half id is compatible with a full id.
		// Generally, when half_id == full_to_half(full_id), return true.
		// But for "Zh, Ch, Sh", if fussy mode is on, half id for 'Z' is compatible
		// with a full id like "Zhe". (Fussy mode is not ready).
		bool half_full_compatible(uint16 half_id, uint16 full_id) const;

		static const SpellingTrie *get_cpinstance();

		static SpellingTrie &get_instance();

		// Save to the file stream
		bool save_spl_trie(FILE *fp);

		// Load from the file stream
        //bool load_spl_trie(FILE *fp);
        bool load_spl_trie(QFile &fp);

		// Get the number of spellings
		size_t get_spelling_num();

		// Return the Yunmu id for the given Yunmu string.
		// If the string is not valid, return 0;
		uint8 get_ym_id(const char *ym_str);

		// Get the readonly Pinyin string for a given spelling id
		const char *get_spelling_str(uint16 splid);

		// Get the readonly Pinyin string for a given spelling id
		const char16 *get_spelling_str16(uint16 splid);

		// Get Pinyin string for a given spelling id. Return the length of the
		// string, and fill-in '\0' at the end.
		size_t get_spelling_str16(uint16 splid, char16 *splstr16,
		                          size_t splstr16_len);
	};
}

#endif  // PINYINIME_INCLUDE_SPELLINGTRIE_H__
